Showing papers on "Trace metal published in 1974"

Mineral and trace-metal balances in children receiving normal and synthetic diets.

Abstract: Eight normal children and eight patients with inborn errors of metabolism have had balance studies performed for the following elements: nitrogen, phosphorus, potassium, sodium, calcium,magnesium, iron, manganese, zinc, copper, molybdenum, cobalt, chromium, nickel, cadmium, stronium, and lead. In six of the patients natural protein was largely replaced by amino acids (Aminogran: Allen & Hanbury Ltd., and MSUD aid: Scientific Hospital Supplies Ltd). Depending upon age they were allowed a variety of other foods such as fruit and vegetables which contain minerals and trace metals. A mineral mixture was provided to augment the trace metal and mineral intake from these allowed food items with the aim of making the total intake comparable with that of healthy children on a free diet. This mixture was shown to be deficient in zinc and manganese. In addition results of the balance studies showed that although the dietary intakes of iron and copper from the synthetic diets were comparable with those of healthy children, the patients retained significantly less of these metals. Appropriate increases of all four metals in the mineral mixture are therefore recommended. A further two patients received an acid hydrolysate of casein (Minafen: Trufood Ltd.) instead of most of the natural protein in the diet. Balance studies indicated that the content of minerals and trace elements was satisfactory. A new mineral and trace metal mixture has been formulated from the intakes of the healthy children. This mixture is sufficient to provide patients receiving synthetic diets in which few or no additional foods are allowed, with adequate amounts of all the essential minerals and trace metals. Iodine, an essential non-metallic element, was not included in this study.

Trace metals in wastewater effluents

Abstract: were determined on a dry weight basis. These were in turn compared with par ticulates from many natural rivers, urban ized storm drainage, and background nat ural sediment to provide quantitative data for evaluating the possible ecological con sequences of various discharges. Galloway3 studied the trace metal con centrations in the area of the outfalls of major discharges in Southern California and found that the average enrichment ratios (the concentration factors relative to the natural concentration of the metal in the sediment for each outfall region) range from as high as 70 for mercury to almost unity for iron, manganese, and nickel. The ratios of other trace metals were scattered in between. These concen trations are not excessively high in com parison with the several hundred enrich ment factors in manganese modules 4 and, to a lesser degree, with the enrichment fac tor of the organic-rich continental shelf.5 Changes are known to occur in the trace metal contents of suspended particulates when they enter the ocean; thus the con centrations in dry weight residues will provide the upper limit of the trace metal contents around the outfall. Because some of the trace metals associated with par ticulates may desorb in the presence of the high concentration of chloride ion in sea water, the actual enrichment factor might well be below that predicted from the determinations of discharge residues.

The Trace Metal Content of Representative Canadian Diets in 1970 and 1971

Abstract: Results are presented for the levels of cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel and zinc in representative Canadian diets for 1970 and 1971. The distribution of each of these trace metals between twelve food groups within the diet are presented and discussed with relation to their relative contribution and possible areas of accumulation. The total amounts of the essential trace metals in the diet are related to recommended allowances, and the harmful trace metals to potential toxicity.

Influence of soluble sewage material on adsorption and desorption behavior of cadmium, cobalt, silver and zinc in sediment-freshwater, sediment-seawater systems

Abstract: The effect of varying concentrations of soluble sewage material in river water on the sorption of Ag, Cd, Co and Zn by suspended freshwater sediments has been studied. Comparison with unpolluted natural sediment systems show that the sorption processes for trace metals are often strongly modified when the river water contains sewage materials.

Determination of heavy metals in municipal sewage plant sludges by neutron activation analysis

Abstract: Research is presented which deals with the use of Neutron Activation Analysis (NAA) to scan sewage sludges for their trace metal content. Of special interest are the metals Hg, Se, Cr, Sb, Co and Fe which are highlighted in sludges from six North Carolina cities that represent the spectrum of rural to heavily industrialized pollution sources. Trace metal content variations and possible meanings for these variations are presented along with the precision and potential of NAA for trace metal scanning.

Removal of Trace Metals During Conventional Water Treatment

Abstract: greater than 23 (i.e., vanadium) except rubidium, strontium, yttrium, cesium, barium, and francium. The significance of trace metals is that they may be toxic to man and other life forms and that man's activities are greatly increasing their level of occurrence above natural environmental concentrations. The toxicity of a given trace metal will be dependent on the total amount ingested as well as a number of other factors of which only some are known and understood; however, this study will be limited to exposure via drinking water. The results obtained during this study for source and drinking waters are part of a larger study during which conventional water and associated waste water-treatment plants were sampled in California and Colorado. Only the results for watertreatment plants will be presented here. There is, however, a close interrelationship between waterand wastewatertreatment plants that should be recognized. Many downstream water-treatment plants treat source waters that are in part composed of wastewater-treatment-plant effluent. The necessity of re-

Implication of the transfer of trace metals from sewage sludge to man

Abstract: Twenty five trace elements have been detected in sewage sludges, and of these lead and cadmium content are of particular importance in relation to the extent to which they may constitute a hazard to health (by direct or indirect transfer to man). The trace metal content of sludges depends on both the quantity and quality of domestic sewage and industrial effluent; after deposition on soil, their availability to plants and groundwater varies with the physical and chemical properties of the soil. Lead and Cd were found to accumulate in farm soil heavily treated with sewage and undigested sludge but not in grassland regularly receiving low doses of liquid sludge. Lead and Cd may reach man in food of either animal or vegetable origin. The contribution of these toxic metals to the total dietary intake of man in England and Wales is at present considered to be acceptably low. Studies on cattle grazed on sludge treated pastures did not show a significant increase in the total Pb or Cd content of milk or muscle when compared with samples from cattle fed on untreated pasture. The liver Pb and Cd content of cattle from treated pastures did not indicate that this meatmore » was unfit for human consumption. 26 references, 7 figures, 3 tables.« less

Uptake and distribution of airborne trace metals in man

Abstract: Tissues obtained at autopsy of New York City residents have been analyzed for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Tissue concentrations were determined for the right lung, hilar lymph nodes, kidney, liver, vertebrae and blood of each subject. Estimates of the deposition and clearance of the above trace metals in the human lung are predicted using a compartmental model. The coefficients of the differential equations have been determined using the data we have contained in conjunction with our results for the trace metal concentrations in the New York City aerosol. Comparison of the deposition and clearance coefficients is made with those proposed by the ICRP Task Group. 8 references, 4 figures, 3 tables.

Manganese, zinc and copper in water, sediments and mussels in north Central Texas reservoirs

Abstract: Manganese, zinc and copper were analyzed in freshwater mussels (Anodonta grandis and Amblema perplicata), water and sediments from four reservoirs in north central Texas The gill, mantle, digestive tract and foot of individual mussels were dissected, reflux digested with concentrated HNO/sub 3/ and analyzed by atomic absorption Comparing the four anatomical parts, the average Cu concentration was highest (4 ppM) in the digestive tract whereas the gills had the highest average concentrations of Zn (25 ppM) and Mn (468 ppM) Trace metal variations among individual mussels from identical localities within a given lake suggests that unpredictable adsorption mechanisms rather than physiological functions are largely responsible for the concentrations Correlation coefficients between mussel shell size and metal concentrations were less than 053 The mean concentrations of Mn (009 ppM), Zn (< 001 ppM) and Cu (001 ppM) in filtered (045 mu) water were identical with unfiltered water Analysis was done by atomic absorption following concentration by evaporation Concentrations of the same metals in sediments from the four lakes were determined following two separate extraction procedures, one using 1 M NH/sub 4/Ac and one using 20% H/sub 2/SO/sub 4/ The average values found (in order of acetate and sulfuric extraction, in ppM)more » were: Mn, 4 and 110; Zn, < 1 and 6; Cu, < 02 and 5 Concentration of metals by various tissues of the mussels over water concentrations is high, ranging from 40-950 fur Cu, 380-4480 for Zn and 28-10,260 for Mn 9 references, 2 figures, 1 table« less